1. Field of the Invention
This invention is directed to coating compositions of acrylic fluorocarbon polymers and fluorinated polyisocyanates that remain relatively dirt free under exterior use conditions and are easily cleaned for example by washing with water when soiled.
2. Description of the Prior Art
Acrylic fluorocarbon polymer containing coating compositions that contain relatively small amounts of fluorocarbon constituents having resistance to crateting are shown in Chang U.S. Pat. No. 4,371,657 issued Feb. 1, 1983 and Chang U.S. Pat. No. 4,396,680 issued Aug. 2, 1983. Coating compositions of blends of acrylic polymers and acrylic polymer containing fluorocarbon constituents that form antiicing coatings are well known. Clear coats containing acrylic polymers having small amounts of fluorocarbon constituents that are applied over metallic base coats to provide auto finishes that have good weatherability, have high water and oil repellence and stain resistance are shown in Sugimura et al U.S. Pat. No. 4,812,337 issued Mar. 14, 1989.
Fluorinated polyurethanes that are used as soil release agents are shown in Gresham U.S. Pat. No. 3,759,874 issued Sep. 18, 1973. Polyurethanes of fluorinated isocyanates that are used as adhesives are shown in Mitsch U.S. Pat. No. 3,972,856 issued Aug. 3, 1976. Protective coatings of fluorinated polyurethanes of fluorinated diols or triols are shown in Re et al U.S. Pat. No. 4,782,130 issued Nov. 1, 1988.
There is a need for a coating composition that provides for soil resistance, is easily cleaned, has a low content of fluorocarbon constituents which reduces the cost of the composition since fluorocarbon monomers are expensive, and gives a coating that is high in solids that can be applied with conventional equipment and cures to a hard, tough, durable and weatherable finish without baking at elevated temperatures.